local Revision = require("git.core.revision")
local h = require("test.git.helpers")
local t = require("test")

---@return integer[]
local function diff_wins()
    local wins = {}
    for _, win in ipairs(vim.api.nvim_tabpage_list_wins(0)) do
        if vim.wo[win].diff then
            table.insert(wins, win)
        end
    end
    return wins
end

---@param role "left"|"right"
---@return integer
local function vertical_diff_win(role)
    local wins = diff_wins()
    table.sort(wins, function(a, b)
        return vim.api.nvim_win_get_position(a)[2]
            < vim.api.nvim_win_get_position(b)[2]
    end)
    local win = role == "left" and wins[1] or wins[#wins]
    if not win then
        error("diff window not found")
    end
    return win
end

---@param dir string
local function cleanup_dir_buffers(dir)
    for _, buf in ipairs(vim.api.nvim_list_bufs()) do
        local name = vim.api.nvim_buf_get_name(buf)
        if name:find(dir, 1, true) then
            pcall(vim.api.nvim_buf_delete, buf, { force = true })
        end
    end
end

t.test("open from worktree focuses the index pane", function()
    local dir = h.make_repo({ ["a.txt"] = "old\n" })
    t.write(dir, "a.txt", "new\n")
    vim.cmd.edit(vim.fs.joinpath(dir, "a.txt"))

    local current_buf = vim.api.nvim_get_current_buf()
    require("git.diffsplit").open()

    t.wait_for(function()
        return #diff_wins() == 2
    end, "diff windows to open")

    t.eq(vim.api.nvim_get_current_win(), vertical_diff_win("left"))
    t.truthy(
        vim.api.nvim_get_current_buf() ~= current_buf,
        "worktree buffer should lose focus"
    )
end)

t.test("open from index focuses the worktree pane", function()
    local dir = h.make_repo({ ["a.txt"] = "old\n" })
    t.write(dir, "a.txt", "new\n")
    local r = assert(require("git.core.repo").resolve(dir))
    local index_buf = require("git.object").buf_for(
        r,
        Revision.new({ stage = 0, path = "a.txt" })
    )
    vim.api.nvim_set_current_buf(index_buf)

    require("git.diffsplit").open({ layout = "vertical" })

    t.wait_for(function()
        return #diff_wins() == 2
    end, "diff windows to open")

    local right = vertical_diff_win("right")
    t.eq(
        vim.api.nvim_get_current_win(),
        right,
        "worktree buffer should be focused"
    )
    t.truthy(
        vim.api.nvim_get_current_buf() ~= index_buf,
        "index buffer should lose focus"
    )
end)

t.test("open_pair keeps old on the left when splitright is set", function()
    local dir = vim.fn.tempname()
    vim.fn.mkdir(dir, "p")
    t.defer(function()
        cleanup_dir_buffers(dir)
        vim.fn.delete(dir, "rf")
    end)

    local old = vim.fs.joinpath(dir, "old.txt")
    local new = vim.fs.joinpath(dir, "new.txt")
    vim.fn.writefile({ "old" }, old)
    vim.fn.writefile({ "new" }, new)

    local prev_splitright = vim.o.splitright
    vim.o.splitright = true
    t.defer(function()
        vim.o.splitright = prev_splitright
    end)

    local old_buf = vim.fn.bufadd(old)
    local new_buf = vim.fn.bufadd(new)
    vim.fn.bufload(old_buf)
    vim.fn.bufload(new_buf)

    require("git.diffsplit").open_pair(old_buf, new_buf, {
        layout = "vertical",
    })

    t.wait_for(function()
        return #diff_wins() == 2
    end, "diff windows to open")

    local left = vertical_diff_win("left")
    local right = vertical_diff_win("right")
    t.eq(vim.api.nvim_win_get_buf(left), old_buf, "old pane should be left")
    t.eq(vim.api.nvim_win_get_buf(right), new_buf, "new pane should be right")
    t.eq(
        vim.api.nvim_get_current_win(),
        right,
        "new pane should be focused by default"
    )
end)